Phosphorylation of endothelial NOS contributes to simvastatin protection against myocardial no-reflow and infarction in reperfused swine hearts: partially via the PKA signaling pathway

Abstract

Aim: The cholesterol-lowering drugs statins could enhance the activities of endothelial nitric oxide synthase (eNOS) and protect myocardium during ischemia and reperfusion. The aim of this study was to examine whether protein kinase A (PKA) was involved in statinmediated eNOS phosphorylation and cardioprotection. Methods: 6-Month-old Chinese minipigs (20-30 kg) underwent a 1.5-h occlusion and 3-h reperfusion of the left anterior descending coronary artery (LAD). In the sham group, the LAD was encircled by a suture but not occluded. Hemodynamic and cardiac function was monitored using a polygraph. Plasma activity of creatine kinase and the tissue activities of PKA and NOS were measured spectrophotometrically. p-CREB, eNOS and p-eNOS levels were detected using Western blotting. Sizes of the area at risk, the area of no-reflow and the area of necrosis were measured morphologically. Results: Pretreatment of the animals with simvastatin (SIM, 2 mg/kg, po) before reperfusion significantly decreased the plasma activity of creatine kinase, an index of myocardial necrosis, and reduced the no-reflow size (from 50.4%±2.4% to 36.1%±2.1%, P<0.01) and the infarct size (from 79.0%±2.7% to 64.1%±4.5%, P<0.01). SIM significantly increased the activities of PKA and constitutive NOS, and increased Ser 133 p-CREB protein, Ser 1179 p-eNOS, and Ser 635 p-eNOS in ischemic myocardium. Intravenous infusion of the PKA inhibitor H-89 (1 μg·kg -1 ·min -1 ) partially abrogated the SIM-induced cardioprotection and eNOS phosphorylation. In contrast, intravenous infusion of the eNOS inhibitor L-NNA (10 mg·kg -1 ) completely abrogated the SIM-induced cardioprotection and eNOS phosphorylation during ischemia and reperfusion, but did not affect the activity of PKA. Conclusion: Pretreatment with a single dose of SIM 2.5 h before reperfusion attenuates myocardial no-reflow and infarction through increasing eNOS phosphorylation at Ser 1179 and Ser 635 that was partially mediated via the PKA signaling pathway.

Sevoflurane postconditioning protects against myocardial ischemia/reperfusion injury by restoring autophagic flux via an NO-dependent mechanism

“…NO is a unique, endogenous regulatory molecule involved in various physiological processes. NO exerts some beneficial effects during myocardial reperfusion, including regulation of myocardial contractility, as well as effects on sarcolemmal and mitochondrial K ATP channel opening, antioxidant effects, and oxygen free radical production [23,24]. Although myocardial I/R may impair NO release, isoflurane exposure has been found to stimulate vascular endothelial cells to produce more NO in the ischemic-reperfused myocardium [16].…”

Cardiac Microvascular Barrier Function Mediates the Protection of Tongxinluo against Myocardial Ischemia/Reperfusion Injury

“…Pharmacological preconditioning(10 groups, n = 8 each): doses based on clinical usage in acute coronary syndrome and previous animal studies, with the following medicines intragastrically (i.g.) administered 1-h before LAD ligation: TXL(50 mg/kg, Yiling Co., Ltd., China)[ 4 ], valsartan(2 mg/kg, Novartis Co., Ltd., USA), rosuvastatin (4 mg/kg, AstraZeneca Co., Ltd., China), simvastatin (2 mg/kg, Merck Co., Ltd., USA) [ 24 , 25 ] and carvedilol (1 mg/kg, Roche Co., Ltd., Switzerland). Tirofiban (Yuanda Co., Ltd., China) was given as a 15 μg/kg intravenous (i.v.)…”

Simvastatin-enhanced expression of promyogenic nuclear factors and cardiomyogenesis of murine embryonic stem cells

“…Recently, we and others have shown that the cholesterol lowering drug statins can improve the ability of cardiovascular stem cells to resist inflammation [25] and repair and regenerate the heart damaged by ischemia or infarction [22,23,38,47]. Statins selectively inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, a rate-limiting enzyme catalyzing the conversion of HMG-CoA to mevalonic acid and thereby attenuate endogenous biosynthesis of cholesterol.…”